Recharge systems for protecting and enhancing groundwate

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MAR strategies / Sustainability of managing recharge systems 841
Figure 2. Groundwater flow systems normally attain equilibrium prior
to the hydrochemical system within (compare a with b). After Stuyfzand (1999).
The combi Cl and oxygen-18
The combination of two conservative tracers like chloride and 18 O is highly recommended, as the individual tracer
may not result in a clear distinction between 2 hydrosomes, especially when the seasonal fluctuations in both
overlap (Fig. 3). The anomalously low δ 18 O value for Rhine water in the Netherlands is explained by its main
provenance in Switzerland and Southern Germany, where precipitation is depleted in 18 O.
The Cl /Br-ratio
Many infiltrated surface waters can be recognized from groundwater recharged by local rain water, by way of their
anomalously high Cl/Br-ratio, at least in coastal areas (Fig. 4). Their high Cl/Br-ratio is related to the low bromide
content of salt waste discharged into many surface waters, either by salt mines or house holds. The Rhine River
10 – 16 June 2005, Berlin ■ 5th International Symposium ■ AQUIFER RECHARGE ■ ISMAR 2005